Solvent refining of hydrocarbon oil



Patented May 7, 1935 UNITED STATES PATENT OFFICE I 1 7 2,000,690 SOLVENT REFINING or HYDROCARBON on.

Louis A. Clarke, Fishkill, N. Y., assignor to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Application November 3, 1933,

Serial No. 696,540

2 Claims.

The foregoing solvent liquids are suitable for extracting undesired constituents from mineral oils, and particularly from lubricating oil fractions.

Lubricating oils, such as produced from midcontinent crude, are ordinarily composed of relatively paraffinic constituents, and also relatively non-paraffinic constituents,including naphthenic, aromatic, and unsaturated hydrocarbon bodies. The solvent of my invention is adapted to extract these relatively non-parafiinic bodies from the oil for the production of lubricating oil fractions which are of relatively high parafiinic character, and therefore of relatively higher viscosity index than the untreated oil.

In the application of my invention to the treatment of mineral oils for the production of lubricating oil, one part of the oil is mixed with about two parts of solvent liquid, and this mixture is then subjected to agitation and heating in order to efieot solution of the undesired constituents of the oil in the solvent. The extent to which the oil is soluble in the solvent will depend upon the nature of the oil as well as upon the condition of temperature and pressure employed. The conditions of temperature and pressure, as well as the ratio of solvent to oil, may be varied for the purpose of effecting the particular degree of extraction desired. The temperatures employed, for example, may range from about 0 F. to 200 F. or thereabouts.

Upon settling, the mixture separates into two layers, one of which comprises the constituents which it is desired to extract from the oil dissolved in the bulk of the solvent liquid, while the other layer comprises the undissolved and relatively other sources.

paraflinic oil in admixture with a relatively small amount of solvent. V

The two layers are then separately withdrawn, and the solvent liquid recovered therefrom. If desired, the separated layers may be subjected to treatment with additional quantities of the solvent for the purpose of obtaining a series of fractions of diiferingcharacteristics.

By way of a specific example, one volume of dewaxed mid-continent distillate oil was mixed with two volumes of benzoylfuran and the mixture heated to about 176? F. At this temperature and while at atmospheric pressure, there was a separation of the mixture into a rafiinate phase and an extract phase, the raffinate phase containing about 70% of the oil while the extract phase contained about 30%.

In some instances, it maybe of advantage to carry out the extraction in the presence of a modifying solvent liquid, such as benzol or a light petroleum naphtha, for the purpose of facilitating the extraction and further controlling the extent thereof. A suitable modifying solvent for this purpose may comprise propane or butane.

The lubricating oil distillate may be subjected to the foregoing extraction treatment, either before or after dewaxing, or subsequent to treat ment with other solvents or chemicals. The invention is not necessarily limited to the treatment of lubricating oil fractions, since the solvent may be adapted to the refining and purification of various hydrocarbon or mineral oil fractions, including naphtha, cracked naphtha, kerosene, etc., as well as residual or distillate fractions, or products derived from petroleum or By reference to the acyl derivatives of furan in the foregoing specification and inthe appended the oil with a solvent selected from the group desired relatively non-parafiinic constituents therefrom, which comprises extractively treating the oil with an aryl acyl derivative of iuran of the character of benzoyl furan whereby the undesired constituents are separated from the oil as an extract soluble in the solvent liquid.

LOUIS A. 

